Encyclopedia of Planetary Landforms

2015 Edition
| Editors: Henrik Hargitai, Ákos Kereszturi

Stealth Feature (Radar, Mars)

Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-3134-3_543

Definition

Regions on Mars showing unusual, extremely low return (nearly zero, or below the 1-sigma noise value) when probed with 3.5- and 12.6-cm Earth-based radar data.

Interpretation

A deposit of unconsolidated, granular fine-grained (<1 cm) dust or ash or other material with a density less than about 0.5 g/cm3, with a minimum thickness of several meters. Radar absorption is caused by a material without any volume scatterers (rocks > few cm). The characteristic of microwave observations suggests it has very low density (Ivanov et al. 1998, 2006). Some parts of the low-return radar units correlate with portions of the Medusae Fossae Formation (MFF) that are large accumulations of fine-grained, friable deposits. Several hypotheses have been proposed about the origin of the material of the MFF that includes ash flow tuffs or ignimbrites, pyroclastic or aeolian materials, paleopolar deposits or loess, carbonate platforms, ice-rich dusty mantling deposited during high obliquity, or ash...

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References

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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  1. 1.NASA Ames Research Center/NPPMoffett FieldUSA
  2. 2.National Air and Space Museum, Center for Earth and Planetary StudiesSmithsonian InstitutionWashingtonUSA